University of Melbourne research into health industry data has found chiropractors attracted more complaints than physiotherapists and osteopaths but it was a small percentage of practitioners who accounted for one in three chiropractic grievances.

The overall complaint rate for the three professions was eight per 1000 practice years. The chiropractors’ rate (29) was three times higher than osteopaths (10) and six times higher than physiotherapists (5). But most chiropractors had no complaints – 1.3 per cent faced more than one complaint and accounted for almost 36 per cent of the profession’s total complaints.

The retrospective cohort study, published in Chiropractic & Manual Therapies, analysed all formal complaints about all registered chiropractors, osteopaths and physiotherapists in Australia lodged with health regulators from 2011 to 2016.

University of Melbourne Medical School Senior Lecturer Dr Anna Ryan worked on the study with Melbourne School of Population and Global Health Research Fellow Dr Lay San Too and Associate Professor Marie Bismark.

Dr Ryan said more detailed analysis was needed to fully explain the results.

“Clearly the small group of practitioners who are the subject of more than one complaint (70 out of 5450) are having a significant impact on the complaints rate for chiropractors,” Dr Ryan said said.

“Understanding more about this group so that they can be helped to meet their regulatory obligations appears to be a key first step in responding to these data.”

During the study period, 5450 chiropractors, 2241 osteopaths and 31,534 physiotherapists were registered to practice in Australia. Most (92.3 per cent of chiropractors, 97.1 per cent of osteopaths and 98.5 of physiotherapists) had no complaints. In total, 1139 complaints were lodged across the professions.

Across the three professions, practitioners aged 66 years or older had a higher rate of complaints compared with those aged 35 years and younger. Men also had 2.43 times more complaints than women. Around two-thirds of complaints about chiropractors and osteopaths related to professional conduct. One in five complaints about chiropractors related to advertising or fees/honesty.

Dr Ryan said physiotherapy’s smaller number of complaints should be investigated.

“It could be that there are models of care in place in physio settings which are somehow protective against complaints,” she said.

“For example, when patients are treated by teams of professionals in a public health setting, rather than an individual in a private practice, does that improve the quality of care and make concerns less likely to arise? And if so, are there elements of that which can be simulated in some way in private practice to achieve the same benefits for patients?”